1. Field of the Invention
The present invention relates to a semiconductor device, and particularly relates to a semiconductor device having an antifuse element.
2. Description of Related Art
In a semiconductor device, such as DRAM (Dynamic Random Access Memory), a faulty memory cell is replaced with a redundant memory cell to redress damage caused by the faulty cell. The address of the faulty memory cell is programmed into a nonvolatile memory element, such as antifuse element, during the manufacturing stage.
Examples of nonvolatile memory elements include, for example, a fuse circuit, a fuse element, and an antifuse element. The antifuse element in its initial state has both ends insulated from each other, and applying a high voltage across both ends breaks this insulation, thereby puts the antifuse element in a conductive state. Once the insulation between its both ends is broken, the antifuse element in its conductive state cannot returned to its insulated state. Hence irreversible and nonvolatile information storage is achieved.